Five semiconductor-related parameters have been extracted simultaneously from experimental data of cathodoluminescence output collected as a function of electron-beam energy. The extraction technique is based on a recently proposed three-dimensional computer model of cathodoluminescence. It also uses a curve fitting technique based on the minimization of an area error criterion. Computational results show that a unique and unambiguous set of parameter values can be obtained for each set of the experimental data points using the algorithm suggested.